CSCC40 Analysis and Design of Information Systems

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CSCC40Analysis and Design of Information Systems
These lecture slides are provided for the
personal use of students taking CSCC40 in the
Fall term of 2007 at the University of Toronto.
Copying for purposes other than this use, and
all forms of distribution are expressly
prohibited. Some slides are adapted from the
course textbook Object-Oriented Systems Analysis
and Design Using UML. 3rd ed. Bennett, McRobb,
Farmer. McGraw-Hill. 2002.

• The following sources of information are also
  recommended
• Project Management Institute
• Association of Computing Machinery
• IEEE Computer Society

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ACM computing curricula 2001 software
engineering processes requirements and
specifications design validation delivery of
systems evolution project management tools and
environments component-based computing formal
methods reliability
these topics are covered in CSCC40 and CSCD08
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value chain
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missions, strategies and their realization
drives and sets goals
business strategy
where IT can help
what must be done
information systems strategy
hardware capabilities
system requirements
informs and enables
information technology strategy
Fig. 1.10 the relationship between business, IS
and IT strategies
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all systems (manual and/or automated) have these
characteristics
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types of systems
each can be implemented as
online and/or batch distributed and/or
centralized corporate and/or departmental and/or
public
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the three perspectives
technological hardware, networks, databases, CASE
tools ... social how do individuals and
organizations use information, how are they
affected by technology professional practices
and standards, policies, quality practices ...
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personal computers, workstations,
mainframes, hardware components, CPUs, memory,
disks, peripherals palmtops ...
word processing, spreadsheets, presentation
software, website design, web search
engines, document management CASE tools ...
e-mail, fax, wireless communication, telephone, ne
tworks, internet ...
technologies for analysis and design
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Hoffer, George, Valacich. Modern Systems Analysis
and Design. 2nd ed. Addison Welsey 1999.
functional decomposition of business
business function
supporting function
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typical suite of systems
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decomposition of a business system
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conceptual complexity !

• Where does one system end, and another start?
• If a system is a subjective view of reality,
• then whos view do
  we work with?
• How do we cope when
• the system is too large to be understood by any
  one person?
• technology is changing all the time?
• user requirements are changing all the time?
• new development tools and techniques and
  methodologies
• are constantly needed?

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we have coping strategies !
methodologies waterfall, prototype, extreme . .
. time-tested techniques for verification,
validation, estimating . . . abstraction and
decomposition modeling methods structured,
object-oriented . . . tools for project
control, design control, configuration
management . . .
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what we want to avoid / prevent ...
from end users perspective ... What system? I
havent seen a new system. (vaporware) It might
work, but its dreadful to use. (lots of
reasons) Its pretty, but does it do anything
useful? (not an improvement)
from clients perspective ... If Id known the
real price, Id never have agreed. Its no use
delivering it now we needed it last April. OK,
so it works, but the installation was such a
mess, my staff will never trust it. I
didnt want it in the first place. Everythings
changed now we need a completely
different system.
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what we want to avoid / prevent ...
from the developers perspective ... We built
what they said they wanted. There wasnt enough
time to do it any better. Dont blame me Ive
never done O-O analysis before. How can I fix it
I dont know how its supposed to work. We said
it was impossible, but no-one listened. The
systems fine the users are the problem.